纳米煤制备及其改善煤泥浮选的机理研究

Preparation of Nano Coal and its Mechanism of Improvement on Coal Flotation

为了探究普通浮选药剂里加入纳米级煤对煤泥浮选的影响,采用冷冻研磨的方法制备了纳米级超纯煤,并对其表面特性进行了分析。在煤浮选捕收剂正十二烷中加入纳米煤,制备液固混合浮选捕收剂用于煤泥浮选。通过X射线光电子能谱(XPS)结合润湿性分析表明,纳米煤颗粒主要以C元素为主,表面官能团以疏水性基团C-C和C=C为主,具有极强的疏水性。研究了正十二烷和纳米煤—正十二烷混合捕收剂对煤泥浮选的效果,并且通过扫描电子显微镜(SEM)对2种捕收剂作用后的精煤颗粒表面形貌进行分析表征。结果表明使用纳米煤-正十二烷混配的新型捕收剂得到的精煤颗粒表面微纳颗粒显著增加,说明纳米煤颗粒在浮选过程中能够粘附于煤颗粒表面,从而增强煤的疏水性,并且增加了煤表面的固体凸起点。在浮选过程中,当气泡粘附煤颗粒时,这些微纳颗粒能够加速水化膜的破裂,促进煤颗粒和气泡的黏附效率,提高煤泥浮选效率。

In order to explore the effect of adding nano coal particles into ordinary flotation collector reagent on coal flotation,coal nanoparticles were prepared by cryogenic-grinding,and the surface characteristics of nano coal particles were analyzed.Furthermore,nano coal particles were added to n-dodecane,which is a traditional coal flotation collector,to make a liquid-solid flotation collector for coal flotation.The X-ray photoelectron spectroscopy(XPS)spectrum showed that nano coal particle mainly contain carbon,and its surface functional groups are mainly C-C and C=C.The flotation efficiency of the mixed flotation collector was investigated and compared.The morphology of clean coal particles were characterized by electron scanning microscope(SEM).Results showed that nano coal particles were clung on the surface of clean coal particles.Nano coal particles on coal surface can improve the hydrophobicity and increase the solid convex point on the coal surface,thus the adhesion efficiency between coal particles and bubbles could be promoted,and the efficiency coal slurry flotation could also be improved.